Tape printing apparatus

Abstract

There is provided provide a tape printing apparatus which is capable of properly operating a tape feed mechanism and a tape cutting mechanism by the use of a single motor. The tape printing apparatus is capable of printing on a printing tape while feeding the printing tape by unwinding a roll of the printing tape, and cutting off a printed portion of the printing tape. A tape feed mechanism feeds the printing tape. A tape cutting mechanism cuts the printing tape. A single motor is capable of performing rotation in normal and reverse directions. A feed mechanism-side gear train transmits torque of the motor to the tape feed mechanism to cause the tape feed mechanism to operate. A cutting mechanism-side gear train transmits the torque of the motor to the tape cutting mechanism to cause the tape cutting mechanism to operate. A clutch mechanism is interposed between the motor, and the feed mechanism-side gear train and the cutting mechanism-side gear train, for performing switching operation to selectively transmit the torque of the motor in one of the normal and reverse directions to the feed mechanism-side gear train, and the torque of the motor in another of the normal and reverse directions to the cutting mechanism-side gear train.

What is claimed is:  
     
       1. A tape printing apparatus which is capable of printing on a printing tape while feeding said printing tape by unwinding a roll of said printing tape, and cutting off a printed portion of said printing tape, 
       the tape printing apparatus comprising:  
       a tape feed mechanism for feeding said printing tape;  
       a tape cutting mechanism for cutting said printing tape;  
       a single motor which is capable of performing rotation in normal and reverse directions;  
       a first torque transmitting mechanism for transmitting torque of said motor to said tape feed mechanism to cause said tape feed mechanism to operate;  
       a second torque transmitting mechanism for transmitting said torque of said motor to said tape cutting mechanism to cause said tape cutting mechanism to operate; and  
       a clutch mechanism interposed between and selectively coupling said motor to said first torque transmitting mechanism and to said second torque transmitting mechanism, the clutch mechanism performing switching operation to selectively transmit said torque of said motor to said first torque transmitting mechanism when said motor rotates in one of said normal and reverse directions, and to transmit said torque of said motor to said second torque transmitting mechanism when said motor rotates in another of said normal and reverse directions.  
     
     
       2. A tape printing apparatus according to  claim 1 , including an output gear from which said torque of said motor is output, and a rotational shaft on which said output gear is rigidly fitted, and 
       wherein said first torque transmitting mechanism includes a feed mechanism-side gear train for transmitting said torque of said motor to said tape feed mechanism, said feed mechanism-side gear train having an input gear, and said second torque transmitting mechanism includes a cutting mechanism-side gear train for transmitting said torque of said motor to said tape cutting mechanism, said cutting mechanism having an input gear,  
       wherein said clutch mechanism includes a planet gear mating with said output gear, and a carrier having one end thereof supporting said planet gear such that said planet gear is rotatable thereon and another end thereof loosely fitted on said rotational shaft on which said output gear is rigidly fitted such that said carrier is capable of pivotal movement, by frictional drag, with rotation of said rotational shaft,  
       said planet gear being mated with said input gear of said feed mechanism-side gear train by said rotation of said motor in said one of said normal and reverse directions, and mated with said input gear of said cutting mechanism-side gear train by said rotation of said motor in said another of said normal and reverse directions.  
     
     
       3. A tape printing apparatus according to  claim 2 , including an ink ribbon to be fed in a state placed upon said printing tape, 
       wherein said tape feed mechanism includes a platen for feeding said printing tape and said ink ribbon in a state placed one upon another, a platen shaft for rotating said platen, a ribbon take-up reel for taking up said ink ribbon, and a ribbon take-up shaft for rotating said ribbon take-up reel, and  
       said feed mechanism-side gear train including a platen gear on which said platen shaft is coaxially secured and a take-up gear on which said ribbon take-up shaft is coaxially secured, as respective output ends thereof.  
     
     
       4. A tape printing apparatus according to  claim 2 , wherein said tape cutting mechanism includes a stationary blade and a movable blade that perform relative motion therebetween for cutting operation, and a crank disk for engaging with said movable blade to cause said movable blade to effect said cutting operation, and 
       said cutting mechanism-side gear train including a cutter gear coaxially secured to said crank disk as an output end of said cutting mechanism-side gear train.  
     
     
       5. A tape printing apparatus according to  claim 3 , wherein said tape cutting mechanism includes a stationary blade and a movable blade that perform relative motion therebetween for cutting operation, and a crank disk for engaging with said movable blade to cause said movable blade to effect said cutting operation, and 
       said cutting mechanism-side gear train including a cutter gear coaxially secured to said crank disk as an output end of said cutting mechanism-side gear train.  
     
     
       6. A tape printing apparatus according to  claim 4 , including a tape exit from which said printed portion of said printing tape is discharged, and a tape holding mechanism associated with said tape exit and linked to said tape cutting mechanism, for holding said printed portion cut off by said tape cutting mechanism. 
     
     
       7. A tape printing apparatus according to  claim 5 , including a tape exit from which said printed portion of said printing tape is discharged, and a tape holding mechanism associated with said tape exit and linked to said tape cutting mechanism, for holding said printed portion cut off by said tape cutting mechanism at said tape exit. 
     
     
       8. A tape printing apparatus according to  claim 6 , including a control block for controlling the rotation of said motor, and wherein said control block controls the rotation of said motor such that when said movable blade has reached a cutting terminal portion as an end position in a cutting direction of said movable blade by said rotation of said motor in said another of said normal and reverse directions, said printed portion is held at said tape exit by said tape holding mechanism. 
     
     
       9. A tape printing apparatus according to  claim 7 , including a control block for controlling the rotation of said motor, and wherein said control block controls the rotation of said motor such that when said movable blade has reached a cutting terminal portion as an end position in a cutting direction of said movable blade by said rotation of said motor in said another of said normal and reverse directions, said printed portion is held at said tape exit by said tape holding mechanism. 
     
     
       10. A tape printing apparatus according to  claim 8 , including a printing block for printing on said printing tape, and wherein said motor includes a rotational shaft, and wherein said crank disk has a peripheral surface and a recess formed in said peripheral surface, said recess having an arcuate profile in cross-section, and wherein said control block includes an encoder arranged in proximity to said rotational shaft of said motor, for detecting a rotational angle through which said rotational shaft of said motor rotates, and a detection switch in abutment with said peripheral surface of said crank disk, said detection switch moving into said recess when said movable blade has reached a cutting wait position, and generating a cutting wait position detection signal indicative of said cutting wait position of said movable blade, and wherein said control block causes said motor to rotate in said another of said normal and reverse directions in response to a print command to thereby cause said movable blade to be pivotally moved to said cutting wait position, and in response to said cutting wait position detection signal, causes said motor to rotate in said one of said normal and reverse directions to thereby cause said movable blade to be held at said cutting wait position and at the same time cause said tape feeding mechanism to feed said printing tape, and wherein upon termination of said printing, said control block causes said motor to rotate in said another of said normal and reverse directions to cause said movable blade to be pivotally moved from said cutting wait position to said cutting terminal position until said encoder detects a predetermined rotational angle through which said rotational shaft of said motor has rotated when said movable blade has reached said cutting terminal position, and then causes said motor to stop to thereby cause said tape holding mechanism to hold said printed portion of said printing tape at said tape exit. 
     
     
       11. A tape printing apparatus according to  claim 9 , including a printing block for printing on said printing tape, and wherein said motor includes a rotational shaft, and wherein said crank disk has a peripheral surface and a recess formed in said peripheral surface, said recess having an arcuate profile in cross-section, and wherein said control block includes an encoder arranged in proximity to said rotational shaft of said motor, for detecting a rotational angle through which said rotational shaft of said motor rotates, and a detection switch in abutment with said peripheral surface of said crank disk, said detection switch moving into said recess when said movable blade has reached a cutting wait position, and generating a cutting wait position detection signal indicative of said cutting wait position of said movable blade, and wherein said control block causes said motor to rotate in said another of said normal and reverse directions in response to a print command to thereby cause said movable blade to be pivotally moved to said cutting wait position, and in response to said cutting wait position detection signal, causes said motor to rotate in said one of said normal and reverse directions to thereby cause said movable blade to be held at said cutting wait position and at the same time cause said tape feeding mechanism to feed said printing tape, and wherein upon termination of said printing, said control block causes said motor to rotate in said another of said normal and reverse directions to cause said movable blade to be pivotally moved from said cutting wait position to said cutting terminal position until said encoder detects a predetermined rotational angle through which said rotational shaft of said motor has rotated when said movable blade has reached said cutting terminal position, and then causes said motor to stop to thereby cause said tape holding mechanism to hold said printed portion of said printing tape at said tape exit. 
     
     
       12. A tape printing apparatus according to claims  6  or  7 , wherein said tape holding mechanism includes a holding nail for holding said printed portion by pressing the same against a stationary blade-side opening wall of said tape exit, a nail holder in the form of a case supporting the holding nail for reciprocating movement, and a coil spring for urging said holding nail toward said stationary blade-side opening wall. 
     
     
       13. A tape printing apparatus according to  claim 12 , wherein said holding nail is comprised of a nail slidably extending through a first hole formed through a movable blade side opening wall and a second hole formed through a wall of said nail holder, and a rod extending linearly from an extreme root end of said nail and including a reduced-diameter portion slidably extending through a third hole formed through said wall of said nail holder. 
     
     
       14. A tape printing apparatus according to  claim 13 , wherein said holding nail has forward and rearward portions, said nail formed in said forward portion and said reduced-diameter portion of said rod formed in said rearward portion are supported by said nail holder so that said holding nail can reciprocate between a holding position at which said nail is held in abutment against said stationary blade-side opening wall in a state projected from said movable blade-side opening wall via said first hole and a release position at which said nail is in a retracted state toward an inside of said movable blade-side opening wall via said first hole. 
     
     
       15. A tape printing apparatus according to  claim 14 , wherein said holding nail has a forward end face formed to have a shape complementary to that of said stationary blade-side opening wall such that said forward end face can be held in surface contact with a surface of said stationary blade-side opening wall. 
     
     
       16. A tape printing apparatus according to  claim 14 , wherein said holding nail further comprises an engaging projection extending inward from the root of said nail, said coil spring fitted on said rod urges said nail in said projecting direction with one end of said nail held in abutment with said root of said nail and the other end of said nail held in abutment with an inner wall of said nail holder, and said engaging projection of said holding nail is in contact with a back of said movable blade, and thereby said holding nail moves forward and backward according to the cutting operation of said movable blade to project and retract through said first hole of said movable blade-side opening wall.